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GIFT   OF 
Arthur  E.   Moncaster 


Small  Turbines  for 
Electric  Drive 


A  description  with 

suggestions  and  instructions 

for  their 


INSTALLATION 


CARE  AND 


OPERATION 


ENGINEER'S  REFERENCE  BOOK 

Please  keep   this   book   where   your   engineer    can   refer 

to  it  readily 


•     •m. 


\ 


Instruction  Book  WM  105 


Jan.  1913 


The  Westi  n^house 


Small  Turbines  for 
Electric  Drive 


A  description  with 

suggestions  and  instructions 

for  their 


INSTALLATION 

CARE  AND 

OPERATION 


AST    PITTSBUR.G.RA. 


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INTRODUCTORY 

The  following  pages  describe  the  small  turbines  manu- 
factured by  The  Westinghouse  Machine  Co.,  and  are  in- 
tended as  a  guide  for  those  who  have  occasion  to  erect  and 
operate  them.  The  matter  herein  is  confined  to  a  detailed 
description  of  the  construction  together  with  illustrations. 
It  is  believed  that  a  better  knowledge  of  the  operation  of  the 
machines  may  be  imparted  in  this  way  than  by  a  lengthy 
series  of  instructions. 

The  particular  type  of  turbines  herein  described,  is 
intended  for  direct  connection  to  small  direct  current  or 
alternating  current  generators,  in  sizes  from  one  to  300  kilo- 
watts. The  smaller  sizes  are  designed  for  non-condensing 
service  only,  while  the  larger  units  are  built  for  either  con- 
densing or  non-condensing 'operation. 

Full  instructions  covering  the  direct  and  alternating 
current  generators  connected  to  these  turbines  may  be  found 
in  the  following  publications  of  The  Westinghouse  Electric 
&Mfg.  Co.: 

D.  C.  turbo  generators,  Instruction  Book  5107. 

A.  C.  turbo  generators,  Instruction  Book  5024. 


FUNDAMENTAL  PRINCIPLES  OF  SMALL  WESTING- 
HOUSE  STEAM  TURBINES. 

As  in  all  steam  turbines,  the  operation  depends  upon 
the  expansion  of  steam  in  suitably  formed  nozzles  so  that  the 
potential  energy  given  up  during  the  expansion  causes  the 
velocity  of  the  expanded  steam  to  increase — the  velocity  at 
the  outlet  from  the  nozzle  or  nozzles  being  such  that  the 
kinetic  energy  (velocity  energy)  is  substantially  equal  to  the 
energy  given  up  during  the  expansion  in  the  nozzles.  After 
the  expansion  in  the  nozzles,  and  having  converted  the  poten- 
tial energy  in  the  steam  into  kinetic  energy,  means  must  be 
provided  for  converting  the  energy  of  motion  into  mechanical 
work  at  the  shaft.  This  may  be  done  in  a  number  of  different 
ways,  and  the  method  employed  in  the  small  turbines  under 
discussion  depends  almost  wholly  upon  the  operating  condi- 
tions, though  it  is  also  governed  partly  by  the  size  of  the 
turbine  and  the  shaft  speed. 

To  show  more  clearly  the  differences  found  in  the 
working  parts  of  the  smaller  turbines,  the  diagrammatic 
sketches  Figs.  I,  2,  3,  4  and  5  are  presented.  The  principle 
involved  in  all  of  these  is  the  same,  differing  only  in  degree 
of  elaboration  as  higher  powers  and  higher  pressure  ranges 
are  reached. 

The  arrangement  of  Fig.  i  is  the  simplest,  consisting  of 
only  the  nozzle  "A,"  a  single  row  of  rotating  blades  "F,"  and 
the  reversing  chamber  UB,"  which  parts  are  common  to  all 
small  turbines.  Steam  is  admitted  to  the  nozzle  "A"  through 
the  governor  valve,  and  expands  to  approximately  atmos- 
pheric pressure,  thereby  attaining  a  velocity  which  is  about 
four  times  the  velocity  of  the  moving  blades  in  Fig.  I .  Now 
since  the  blades  move  with  about  %  the  velocity  of  the  steam 
leaving  the  nozzle  "A,"  the  steam  after  having  passed  through 
the  moving  blades,  enters  the  reversing  chamber  "B,"  with 
approximately  half  the  nozzle  velocity. 

The  reversing  chamber  "B,"  as  the  name  suggests, 
reverses  the  direction  of  the  steam,  and  causes  it  to  again  im- 
pinge on  the  same  row  of  moving  blades,  further  reducing  the 
velocity  of  the  steam,  and  thus  absorbing  the  energy  remain- 
ing after  the  first  passage  through  the  blades. 

In  the  arrangements  Figures  2,  3  and  4,  the  principle 
of  operation  is  the  same  as  for  Fig.  I,  except  that  instead  of 
completing  the  expansion  in  the  first  nozzle,  the  expansion  is 
carried  down  only  sufficiently  far  to  give  the  steam  the  desired 
velocity,  i.  e.,  approximately  four  times  the  blade  velocity. 


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The  expansion  is  then  completed  in  a  second  nozzle  "C" 
(Fig.  2)  after  which  the  steam  passes  through  the  blades  a 
third  time,  enters  the  reversing  chamber  "D,"  passes  through 
the  same  row  of  blades  a  fourth  time  and  thence  to  the  ex- 
haust. This  may  be  regarded  as  a  combination  of  two  of  the 
elementary  units  shown  in  Fig.  i,  in  the  same  manner  as  two 
cylinders  of  different  sizes  are  put  in  series  to  form  a  compound 
engine.  Thus,  by  a  proper  selection  of  one  of  these  arrange- 
ments, the  turbine  can  be  adapted  to  any  steam  pressure  and 
blade  speed. 

Fig.  3  shows  a  nozzle  arrangement  for  a  condition 
intermediary  between  Figures  I  and  2,  in  which  the  steam 
makes  one  passage  through  the  blades  after  passing  the  second 
nozzle. 

Fig.  4  is  a  combination  occasionally  used,  in  which  the 
element  in  Fig.  i  is  followed  by  two  nozzle  elements,  each  dis- 
charging steam  once  through  the  blade  passages. 

Fig.  5  shows  the  scheme  used  in  some  of  the  larger 
turbines  to  permit  carrying  heavy  overloads,  or  temporary 
operation  with  low  steam  pressure.  Steam  from  the  governor 
valve  is  admitted  to  the  nozzle  "A"  same  as  in  Fig.  i,  but  in 
addition  a  secondary  hand  operated  valve  admits  steam  to  the 
nozzle  "E,"  which  is  also  under  the  control  of  the  governor 
when  in  operation.  It  will  be  noted  that  the  nozzles  "A"  and 
"E"  each  have  an  independent  reversing  chamber,  that  for 
the  nozzle  "E"  being  located  within  that  for  the  nozzle  "A," 
thus  utilizing  the  energy  in  the  steam  with  equal  economy  at 
heavy  overload,  as  well  as  at  normal  rating. 

The  overload  valve  "E"  should  not  be  used,  however, 
except  when  necessary  to  prevent  the  speed  from  falling  and 
lowering  the  voltage,  as  then  the  economy  will  not  be  so  good 
at  fractional  loads. 

General  Features  of  Design. — All  the  turbines,  ex- 
cepting the  10  and  15  Kw.  sizes,  and  smaller,  are  equipped  with 
a  vertical  geared  governor  of  generous  design,  having  great 
power,  operating  at  the  best  speed  for  efficient  and  close 
regulation.  An  extension  of  the  governor  spindle  downwards, 
operates  an  oil  pump  of  simple  design,  for  supplying  the  bear- 
ings with  an  ample  flood  of  oil. 

Fig.  6  is  a  typical  cross  section  of  a  small  turbine,  and 
shows  also  on  the  end  elevation,  the  automatic  stop  and 
governor  valves.  It  will  be  noted  that  the  rotor  carries  but  a 
single  row  of  blades,  which  revolves  between  the  nozzle  blocks 
and  reversing  chamber,  as  previously  described.  These  are 
plainly  indicated  in  the  lower  portion  of  the  machine. 


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All  the  working  parts  of  the  turbine  are  in  the  lower 
half  of  the  cylinder  or  casing,  thus  making  it  unnecessary  to 
disconnect  the  steam  and  exhaust  pipes  when  the  turbine  is 
opened  for  inspection.  Also,  it  permits  the  spindle  to  be 
removed  from  the  casing  without  removing  the  turbine  rotor 
from  the  shaft.  Furthermore  the  governor  (shown  in  greater 
detail  in  Fig.  15)  may  be  removed  from  the  turbine  without  the 
necessity  of  taking  it  apart,  beyond  disconnecting  the  link 
attached  to  the  governor  valve  stem.  The  governor  shown  in 
Fig.  6  is  driven  by  means  of  a  worm  and  wheel,  although  in 
some  cases  bevel  gears  are  used. 

The  oil  pump,  which  is  located  under  the  oil  reservoir, 
is  driven  by  the  governor  spindle. 

This  particular  design  of  governor  may  be  removed 
from  the  turbine  by  simply  removing  the  bolts  on  the  horizon- 
tal joints  and  upper  half  of  the  vertical  joint.  However,  some 
governors  have  the  union  type  coupling  and  cannot  be  removed 
until  the  union  coupling  has  been  disconnected,  the  latter 
being  accessible  through  the  hand-hole  shown  in  the  cross 
section,  Fig.  6. 

In  the  majority  of  small  turbines  there  are  but  two 
bearings,  both  of  which  are  part  of  the  generator,  the  turbine 
rotor  being  carried  on  the  end  of  the  generator  shaft.  In  some 
of  the  larger  sizes,  three  bearings  are  employed,  as  also  in  the 
case  of  small  turbines  for  driving  alternators. 

Rotor. — In  smaller  sizes  up  to  25  Kw.,  the  turbine 
rotor  is  integral  with  the  hub,  but  in  the  larger  sizes  the  rotor 
consists  of  a  hub  to  which  the  turbine  disc  is  bolted,  the  disc 
being  doweled  into  the  hub  to  insure  its  running  true. 

The  blades,  as  will  be  seen  from  the  cross  section  of  the 
rotor,  are  held  in  place  by  means  of  rivets  which  go  through 
the  shanks  of  the  blades  inserted  in  the  periphery  of  the 
turbine  disc. 

The  hubs  of  all  rotors  are  fitted  on  to  the  shaft  with  a 
considerable  taper,  so  that  if  necessary  they  can  be  easily 
removed  by  loosening  the  nut  on  the  shaft  and  tapping  the 
latter  lightly  with  a  babbit  hammer.  The  extension  shaft  for 
driving  the  governor  is  bolted  to  the  rotor  hub  and  carries  the 
outboard  turbine  gland  sleeve  and  also  the  automatic  stop, 
which  will  later  be  taken  up  in  detail. 

In 'the  case  of  alternating  current  units,  it  is,  for  elec- 
trical reasons  practically  impossible  to  split  the  armature 
horizontally,  and  therefore  it  is  necessary  to  withdraw  the  re- 
volving field  from  the  armature  endwise.  For  this  reason, 


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the  turbine  wheel  is  doweled  and  bolted  to  the  governor  drive 
extension  shaft,  which  is  in  turn  doweled  and  bolted  to  the  hub 
on  the  generator  shaft.  It  is  necessary  therefore,  in  disas- 
sembling the  machine,  to  first  remove  the  gland  ring  "A" 
(Fig.  6)  and  remove  the  bolts  "B,"  which  attach  the  governor 
drive  extension  shaft  to  the  hub  "C."  The  revolving  field 
can  then  be  drawn  out  through  the  collector  end  of  the  gener- 
ator. The  hub  "C"  should  not  be  removed  from  the  gener- 
ator shaft  unless  necessary  in  order  to  remove  the  gland  sleeve 
"B."  It  will  be  evident  that  these  fits  should  be  disturbed  as 
little  as  possible,  so  as  to  maintain  the  rotor  running  true. 

In  assembling  the  rotor,  and  all  parts  of  the  interior  of 
the  turbine,  particular  care  should  be  taken  to  ascertain  that 
all  wiring  and  split  pins  for  preventing  the  loosening  of  bolts 
and  nuts  are  in  place  before  the  cylinder  cover  is  put  on.  It 
is  evident  that  considerable  damage  might  result  if  a  bolt  or 
nut  were  to  loosen  and  come  out  while  the  turbine  is  in  opera- 
tion. 

Nozzle  Blocks,  Reversing  Chambers  and  Flexible 
Packings.  In  turbines  operating  on  125  pounds  steam  pres- 
sure, or  less,  the  nozzle  and  reversing  chamber  arrangement 
shown  in  Fig.  i  is  generally  employed,  and  as  previously 
stated,  the  entire  expansion  is  completed  within  the  nozzle. 
There  is  no  tendency  for  the  steam  to  leak  out  of  the  blades  or 
reversing  chambers,  as  the  pressure  in  the  latter  is  the  same  as 
in  the  turbine  casing.  In  the  other  arrangements,  however, 
as  shown  in  Figs.  2  to  5,  as  the  steam  is  only  partly  expanded 
in  the  first  nozzle,  the  steam  is  under  greater  pressure  in  the 
first  reversing  chamber  and  following  nozzles  than  in  the 
casing.  Therefore,  it  is  evident  that  since  it  would  be  an  im- 
possibility to  run  without  clearances  between  the  rotating 
wheel  and  nozzle  blocks,  there  would  be  considerable  leakage 
through  the  clearances  "G"  and  "F"  (Fig.  8),  as  well  as  along 
the  space  between  the  periphery  of  the  wheel  and  the  turbine 
cylinder. 

To  obviate  the  leakages  which  would  occur  with  reason- 
able running  clearances,  a  packing  shown  at  "D"  (Fig.  8)  is 
employed.  This  consists  of  one  or  more  brass  strips  having 
a  lug  "C,"  which  are  inserted  in  undercut  grooves  turned  in 
the  flange  of  the  nozzle  blocks  and  reversing  chambers.  These 
brass  strips,  which  are  made  in  sections  about  3"  long,  are 
pressed  against  the  wheel  by  small  flat  springs  shown  at  "E." 
When  first  inserted  in  the  machine,  the  strips  are  of  such  a 
depth  that  when  pressing  against  the  wheel,  the  lug  "C"  on 

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the  strips  is  a  slight  amount  away  from  the  shoulder  "O"  of 
the  undercut  grooves  in  the  nozzle  block  and  reversing  cham- 
ber flanges.  When  the  turbine  is  put  in  operation,  the  fric- 
tion of  the  brass  strips  on  the  turbine  rotor  wears  away  the 
brass  strips  until  the  lug  "C"  of  the  strips  engages  with  the 
shoulder  "O"  of  the  undercut  grooves,  which  prevents  the 
strips  from  further  wearing  upon  the  turbine  rotor — the  latter 
then  revolving  between  the  strips  without  touching  them,  and 
yet  practically  without  any  clearance.  Thus,  though  the 
clearance  is  reduced  to  practically  nothing  so  far  as  leakage 
is  concerned,  should  for  any  reason  an  actual  displacement  of 
the  rotor  occur,  the  packing  strips  would  simply  be  pushed 
back  against  the  springs,  and  wear  away  without  in  any  way 
injuring  the  rotor  or  turbine. 

The  leakage  which  would  occur  between  the  periphery 
of  the  wheel  and  cylinder  is  prevented  by  packings  which  work 
on  exactly  the  same  principle,  but  are  made  in  the  form  of 
round  or  square  buttons  which  press  against  the  periphery 
of  the  wheel  and  are  shown  at  "I"  in  Fig.  8.  These  buttons 
are  placed  at  the  beginning  and  end  of  each  stage  in  the  tur- 
bine, as  indicated  in  the  small  diagrammatic  sketch  in  the 
upper  part  of  Fig.  8.  In  the  latter,  the  steam  is  under  pressure 
in  the  space  "  K  "  and  would  tend  to  leak  into  the  spaces  "  M  " 
and  "L"  on  the  other  side  of  the  packings  "I."  The  only 
difference  between  the  button  packings  and  the  strip  packings 
is  that  the  former  are  pressed  against  the  rim  of  the  wheel  by 
small  helical  springs,  in  place  of  the  flat  springs  employed  on 
the  circumferential  packings. 

The  packings  employed  require  no  attention  whatever 
for  normal  operation,  but  if  for  some  reason  the  turbine  rotor 
has  been  allowed  to  move  axially,  it  may  be  found  upon 
opening  the  turbine  and  making  an  examination  that  the 
strips  on  the  one  side  of  the  wheel  have  been  worn  away  so 
that  when  the  wheel  is  again  centralized,  the  packing  strips 
on  one  side  or  the  other  may  not  come  in  contact  with  the 
wheel.  If  this  is  found  to  be  the  case,  the  packing  strips 
should  be  removed  and  the  lug  "C"  scraped  away  sufficiently 
to  permit  the  strips  to  bear  lightly  against  the  rotor,  which 
should  be  adjusted  axially  so  that  a  clearance  of  .020"  to 
.025"  exists  on  either  side  of  the  rotor,  between  it  and  the 
nozzle  blocks.  The  position  of  the  wheel  may  be  adjusted  by 
means  of  the  thrust  bearings  as  described  on  page  17,  details 
of  which  are  shown  in  Figure  13.  The  position  of  the  wheel, 
with  reference  to  the  nozzles  and  reversing  chambers,  may  be 

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readily  observed  through  the  hand-hole  in  the  cylinder  cover. 
Renewing  the  packing  strips  is  really  a  trivial  matter. 

All  nozzle  blocks  and  reversing  chambers  are  very 
carefully  scraped  to  a  steam  tight  fit  before  leaving  the  shop. 
As  any  leakage  from  the  nozzles  or  reversing  chambers  will 
impair  the  steam  economy  of  the  turbine,  great  care  should  be 
taken  to  insure  that  the  surface  between  the  nozzle  blocks  and 
the  cylinder  casing,  (as  at  "H,"  Figure  8),  is  a  perfectly  steam 
tight  joint. 

The  general  disposition  of  the  nozzles  and  reversing 
chambers,  with  reference  to  the  wheel,  is  shown  in  Fig.  9. 

Glands. — In  small  non-condensing  turbines,  leakage 
of  steam  from  the  turbine  cylinders  through  the  openings 
through  which  the  shaft  passes,  is  prevented  by  simple  forms 
of  glands  shown  in  detail  in  Figure  10.  As  will  be  noted,  the 
gland  consists  simply  of  a  number  of  special  bronze  snap  rings 
fitted  into  a  cast  iron  sleeve  shrunk  on  the  turbine  shaft,  and 
the  gland  bushing  fitted  to  the  turbine  cylinder  with  a  steam 
tight  joint,  within  which  the  snap  rings  are  fitted.  The  bush- 
ing "G"  (Fig.  10)  is  shown  in  detail.  The  one  point  to  be 
noted  is  the  pocket  "A,"  which  supplies  oil  to  the  space  between 
the  first  and  second  snap  rings,  through  the  hole  "B."  Any 
steam  leaking  past  the  first  and  second  snap  rings  is  free  to 
escape  to  atmosphere  through  the  hole  "C,"  connecting  with 
the  space  "E." 

A  passage  "H"  is  also  shown,  which  connects  to  a 
small  sight  feed  oil  lubricator,  and  also  a  drain  passage  "I," 
which  should  be  connected  to  the  sewer  or  any  other  conven- 
ient point  outside  the  engine  room.  As  the  pressure  within 
the  turbine  cylinder  will  always  be  greater  than  that  of  the 
atmosphere,  there  is  no  chance  for  the  very  small  amount  of 
oil  supplied  to  the  glands  to  get  into  the  exhaust  steam,  as  the 
leakage  is  always  outwards.  To  prevent  a  small  amount  of 
condensation  which  might  leak  past  the  outer  snap  ring,  from 
being  thrown  into  the  engine  room,  or  being  drawn  into  the 
generator  bearing,  a  guard  "J"  is  fitted,  which  effectually 
prevents  the  escape  of  this  water,  which  is  collected  and  taken 
to  a  convenient  point  through  the  drain  "K." 

Care  should  be  observed  that  the  piping  is  arranged  in 
accordance  with  the  foregoing,  and  that  the  rings  are  free  and 
have  a  side  or  axial  clearance  of  about  .001 5"  or  .002"  in  the 
grooves,  and  that  they  are  circular  and  fit  inside  of  the  gland 
ring  " G"  snugly  and  uniformly  all  around,  yet  they  should  not 
grip  tightly  enough  on  the  inside  of  the  sleeve  "G"  to  prevent 

14 


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15 


SECTION  A -A 


FIG.  11 


16 


them   from   being   pushed   axially.     In   operation,   the   rings 
remain  stationary. 

In  some  of  the  larger  non-condensing  turbines,  and 
turbines  designed  for  condensing  operation,  water  glands 
similar  to  those  used  on  the  larger  units  are  employed.  A 
section  of  one  of  these  is  shown  in  Fig.  1 1 .  The  water  supplied 
to  the  gland  inlet  connection  should  be  commensurate  with 
the  back  pressure  to  be  employed — viz.,  it  should  be  5  pounds 
greater  than  the  back  pressure.  All  condensing  turbines 
should  have  their  water  glands  furnished  with  water  at  5 
pounds  pressure  above  atmosphere. 

The  water  glands  are  provided  with  a  water  outlet  con- 
nection as  shown,  which  should  remain  closed  when  the 
turbine  is  operating  condensing.  When  operating  with  back 
pressure,  the  valve  should  permit  a  small  amount  of  water  to 
escape  from  the  glands,  so  as  to  provide  a  slight  circulation 
through  the  glands— thus  maintaining  the  temperature  below 
that  of  evaporation.  Otherwise,  the  water  would  boil  and  the 
steam  formed  would  pass  into  the  engine  room. 

The  most  common  method  of  furnishing  water  of 
requisite  pressure  is  to  connect  the  oil  cooler  with  a  source  of 
water  supply,  afterwards  discharging  this  water  into  an  ele- 
vated overflow  at  the  requisite  height  above  the  axis  of  the 
turbine  to  give  the  proper  pressure — the  pipe  leading  to  the 
overflow  being  provided  with  a  connection  to  the  glands.  The 
provision  of  an  elevated  tank,  furnished  with  a  ball  float  is  an 
alternative  to  be  considered. 

Bearings. — All  bearings  used  on  these  machines  are 
of  the  split  babbitted  type,  oil  being  supplied  from  the  oiling 
system  to  be  described  later,  though  in  some  cases  the  bearings 
are  ring  oiled,  or  have  ring  oiling  in  addition  to  forced  lub- 
rication. 

The  design  of  a  bearing  is  shown  in  Fig.  12.  The  four 
keys  in  the  center,  located  above,  below  and  at  the  sides,  have 
liners  beneath  them,  the  manipulation  of  which  permits  ready 
adjustment  of  the  rotor  up  and  down  and  sideways,  with 
reference  to  the  stationary  elements.  The  inboard  generator 
bearing  also  serves  for  adjusting  the  axial  clearances  of  the 
rotor,  and  it  is  by  means  of  this  that  the  position  of  the  tur- 
bine rotor  with  respect  to  the  nozzle  blocks  and  reversing 
chambers  is  determined.  The  thrust  bearing  journal  and 
means  of  adjustment  is  shown  in  detail  in  Fig.  13.  The 
thrust  collars  "B"  and  "C"  are  provided,  having  a  hollow 
pocket  on  one  side  in  which  split  liners  are  inserted,  shown  at 

17 


"D"  and  "E."  The  distance  between  "B"  and  "C"  is  kept 
constant  and  the  axial  position  of  the  shaft  is  determined  by 
shifting  liners  from  one  end  to  the  other.  Thus,  when  the 
clearances  have  once  been  determined,  if  the  turbine  receives 
proper  attention,  and  if  a  proper  quality  of  oil  is  employed,  re- 
adjustment should  be  unnecessary  for  an  indefinite  period. 
To  insure  satisfactory  running  of  the  bearings,  the  radial 
clearance  allowed  should  be  about  .005"  or  .006",  which  is 
also  about  the  proper  clearance  axially. 

It  must  be  understood  that  in  reality,  the  thrust  bear- 
ing does  not  have  to  take  any  end  thrust,  as  the  pressure  on 
either  side  of  the  revolving  element  of  the  turbine  is  the  same. 
The  sole  purpose  of  the  thrust  bearing  is  to  definitely  maintain 
the  axial  position  of  the  rotor. 

In  regard  to  bearings,  it  may  be  remarked  for  the  bene- 
fit of  those  not  familiar  with  the  operation  of  high  speed 
machinery  that  turbine  bearings  are  operated  at  higher  tem- 
peratures than  those  of  reciprocating  engines,  and  should  a 
bearing  feel  disagreeably  warm  to  the  hand,  it  need  cause  no 
anxiety  to  the  operator.  The  bearings  may  be  operated 
satisfactorily  for  years,  at  a  temperature  of  150  or  160  degrees 
F.,  without  experiencing  any  trouble. 

Governor  and  Oil  Pump.  As  previously  explained, 
with  the  exception  of  the  governors  for  the  10  and  the  15  Kw. 
turbines,  all  are  of  the  vertical  shaft  type,  driven  from  the 
turbine  shaft  either  by  spur  bevel  gearing  or  worm  and  wheel. 
Fig.  1 5  shows  detail  cross  section  through  one  of  the  vertical 
shaft  governors  which  is  typical  of  those  used  on  all  turbines 
except  that  it  does  not  have  the  coupling  between  the 
governor  spindle  and  the  oil  pump  spindle,  as  shown  in  Fig.  6. 

The  principle  upon  which  this  governor  works  is  the 
action  of  centrifugal  force  on  weights  which  are  counter- 
balanced by  means  of  the  helical  spring.  The  governor 
weights,  proper,  are  small  steel  cylinders,  riveted  between  the 
two  governor  weight  arms  made  of  sheet  steel.  At  the  lower 
end  of  the  governor  weight  arms,  and  riveted  between  them 
are  the  governor  arm  blocks  which  carry  the  governor  fulcrum 
knife  edge  and  governor  weight  knife  edge  blocks.  The  latter 
are  locked  into  the  governor  arm  block  and  are  held  from  lateral 
movement  by  the  governor  weight  arms. 

Attached  to  the  governor  spindle  is  the  governor  weight 
disc,  upon  which  are  mounted  the  governor  weight  disc  ful- 
crum blocks,  which  take  the  thrust  of  the  governor  weights. 
Above  the  governor  weight  disc  is  mounted  the  governor 
spring  sleeve,  which  is  loose  on  the  governor  spindle.  This 

19 


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20 


sleeve  transmits  the  pressure  from  the  governor  knife  edges 
to  the  governor  spring,  and  is  connected  by  two  governor 
spring  sleeve  bolts  to  the  governor  sleeve,  which  is  free  to  move 
up  and  down,  and  revolve  upon  the  governor  spindle  bushing. 

The  motion  transmitted  to  the  governor  sleeve  is  im- 
parted to  the  governor  clutch  carrying  the  trunnion  to  which 
the  governor  clutch  levers  are  attached,  and  through  which 
the  motion  of  the  governor  weights  is  transmitted  to  the 
governor  valve,  through  the  governor  clutch  lever  link. 

A  governor  sleeve  nut  is  screwed  on  the  lower  portion 
of  the  governor  sleeve,  to  take  the  upward  thrust  of  the  gover- 
nor sleeve  upon  the  governor  clutch.  This  nut  is  retained  in 
any  position  in  which  it  is  placed,  by  means  of  the  pin  and  cot- 
ter nut  shown  in  the  cross- sectional  view. 

The  adjustment  of  the  governor  for  determining  the 
speed  and  regulation  of  the  turbine  is  obtained  by  means  of 
the  governor  adjusting  spring  nut  and  governor  spring  adjust- 
ing seat.  It  will  be  noted  in  the  section  elevation  and  plan 
view  of  the  governor  that  a  number  of  holes  are  provided  in  the 
flange  on  the  governor  spindle  adjusting  nut,  and  also  in  the 
governor  spring  adjusting  nut  seat,  into  which  a  pin  may  be 
screwed  and  secured  by  the  cotter  pin.  This  permanently 
fixes  any  adjustment  which  has  been  made,  the  governor 
spring  adjusting  nut  seat  being  held  from  turning  on  the 
governor  spindle  by  means  of  a  pin  and  key  way. 

The  lubrication  of  the  various  parts  of  the  governor  is 
secured  by  supplying  oil  under  pressure  through  the  oil  hole 
which  admits  oil  to  the  space  between  the  governor  spindle  and 
upper  governor  spindle  bushings,  through  ports  "A."  From 
the  annular  space  between  the  governor  spindle  and  spindle 
bushing,  the  oil  enters  ports  "  B  "  which  communicate  with  the 
port  "C"  and  supply  oil  to  the  governor  sleeve,  from  which  it 
works  its  way  through  the  ports  "D"  and  "E,"  through  the 
trunnions  of  the  governor  clutch,  and  lubricates  the  governor 
clutch  trunnions.  Part  of  the  oil  supplied  to  the  ports  "B" 
goes  to  the  thrust  bearing  under  the  governor  weight  disc 
which  carries  the  thrust  due  to  the  weight  of  the  governor  and 
governor  spindle.  This  thrust  bearing  consists  of  a  number  of 
alternate  brass  and  steel  rings  which  are  lubricated  from  the 
port  "B." 

The  oil  collecting  in  the  lower  portion  of  the  upper  half 
of  the  gear  case  passes  through  a  port  "  F,"  and  is  led  by  a  pipe 
over  the  gears,  or  worm  and  gear,  keeping  the  latter  flooded 
with  a  supply  of  oil. 

21 


OCA/.  SPRING   ADO.  NUT 

COV.  SPRING    ADJ.  NUT    SCREW 

CO/.  SPRING   ADO.  NUT    SCREW   COTTER 


GCV.  SPRING    ADO.  NUT    SEAT 


GOV.  GEAR    CASE   CAP 


GOV.  GEAR  CASE 
COVER 


GOV.  SPRING 

GOV.  SPRING 

BOLT 


OvJKMFEIEDCE  BLOCK 


RING  UPPER 
UST   RING   LOWEP 


GOV.WORM  OR 
CCV.WORM  GEAP 
SHAFT 


CCV.  GEAR 
LOWER   HAL 


LOWER    GOV. 
SPINDLE    BUSHING 


OIL  PUMP   GEAR    DRIVEN 
SHAFT   BUSHING 


FIG.  15 

22 


A  sight  feed  oiler  is  fitted  to  a  branch  of  the  oil  pipe, 
supplying  the  governor  with  oil,  and  gives  a  constant  visible 
indication  to  the  operator,  of  whether  or  not  the  oil  pump  is 
working  properly.  The  discharge  from  this  sight  feed  empties 
into  the  upper  portion  of  the  governor  case,  and  together  with 
the  oil  thrown  from  the  governor,  lubricates  the  governor  gear 
as  before  mentioned.  It  is  important  that  the  oil  be  contin- 
ually overflowing  at  this  point. 

To  obtain  close  regulation  of  speed,  the  scale  or  degree 
of  compression  of  the  governor  spring  with  a  given  increase  in 
compressor  force  upon  it,  must  be  properly  adjusted  or  the 
governor  will  be  over- sensitive,  or  not  sensitive  enough.  When 
turbines  are  shipped  from  the  shop,  the  governor  has  been  ad- 
justed for  desirable  speed  variations,  but  should  it  become 
necessary  for  any  reason  to  adjust  the  regulation,  this  may  be 
done  by  tightening  or  loosening  the  governor  spring  adjusting 
nut.  If,  upon  trying  adjustments  in  various  positions,  by 
means  of  the  governor  spring  adjusting  nut,  it  is  found  that  the 
governor  is  unstable  and  hunts,  the  number  of  active  coils  of 
the  spring  should  be  reduced  by  screwing  the  spring  farther 
onto  the  governor  spring  adjusting  seat,  thus  increasing  the 
scale  of  the  spring.  However,  if  the  governor  is  not  sufficient- 
ly sensitive,  it  is  an  indication  that  more  coils  of  the  spring  are 
required,  and  the  spring  should  be  unscrewed  from  the  governor 
spring  adjusting  seat.  When  the  proper  number  of  active  coils 
have  been  obtained,  accurate  adjustment  of  the  speed  and 
regulation  can  be  obtained  by  changing  the  position  of  the 
governor  spindle  adjusting  nut.  To  have  close  regulation, 
there  should  be  as  little  lost  motion  as  is  consistent  with  per- 
fect freedom  between  the  valve  stem  and  the  governor  clutch 
sleeve. 

In  adjusting  the  governor  valve,  the  operator  should 
make  sure  that  the  governor  valve  seats  tightly  before  the 
governor  reaches  its  extreme  outer  position.  Otherwise,  the 
turbine  is  likely  to  go  above  normal  speed  and  trip  the  auto- 
matic throttle.  If  it  is  found  that  the  turbine  runs  above 
normal  speed  and  trips  the  automatic  throttle  valve,  when 
operating  without  load  on  the  generator,  the  governor  valve 
stem  should  be  lengthened  by  loosening  the  governor  valve 
stem  lock  nut  and  unscrewing  the  valve  stem  from  the  upper 
governor  valve  stem  end,  thus  lengthening  the  valve*|stem  and 
bringing  the  valve  down  to  its  seat.  Too  much  lengthening  of 
the  valve  stem  will  preclude  a  full  valve  opening,  preventing  the 
turbine  from  carrying  its  proper  loads.  Assurance  should  be 
had  that  the  valve  is  steam  tight,  and  is  properly  ground  in. 

23 


The  oil  pump  is  located  below  the  oil  reservoir, 
and  consists  of  two  spur  gears,  one  of  which  is  keyed  to  the 
lower  governor  spindle,  and  the  other  mounted  on  an  idle 
shaft  running  in  bronze  bushings.  The  principle  of  operation 
is  based  on  the  fact  that  where  the  gears  mesh  together,  the  oil 
is  forced  out  from  between  the  teeth,  whereas  around  the  peri- 
phery, the  openings  are  flooded  with  oil,  which  is  carried 
around  from  the  inlet  to  the  discharge  side.  No  valves  are 
required  in  this  type  of  pump,  and  as  it  is  entirely  flooded  with 
oil,  no  attention  should  be  needed.  The  clearance  between  the 
outer  diameter  of  the  teeth  and  the  gear  casing  should  be 
about  .005"  as  should  also  be  the  clearance  .between  the  root 
of  one  gear,  and  the  top  of  the  teeth  of  the  other.  The  ver- 
tical clearance  between  the  gears  and  the  casing  should  be 
about  .005",  which  is  the  thickness  of  the  gasket  put  between 
the  oil  pump  case  and  the  bottom  of  the  oil  reservoir.  In  this 
connection,  it  must  be  noted  that  care  must  be  taken  in  cut- 
ting out  this  gasket,  and  also  that  the  portion  cut  out  for  the 
gears  and  the  oil  intake  and  discharge  are  clean  cut,  to  prevent 
pieces  of  gasket  from  getting  into  the  gears. 

An  oil  gauge  is  fitted  on  each  oil  reservoir  to  show  the 
amount  of  oil  in  the  system,  and  the  oil  should  be  carried 
within  about  an  inch,  or  inch  and  a  half  of  the  top  of  the  gauge, 
when  the  turbine  is  standing  idle. 

Automatic  Stop  Governor.  A  detail  cross  section 
through  the  automatic  stop  governor  is  shown  in  Fig.  14,  and 
in  Fig.  1 6  its  connection  to  the  throttle  valve.  The  stop 
proper  is  contained  within  the  governor  drive  extension  shaft, 
and  consists  of  a  plunger  "A"  and  spring  "B."  Adjusting 
liners  are  inserted  or  removed  from  "C"  for  changing  the 
speed  at  which  it  trips. 

As  indicated  in  the  diagrammatic  sketch,  the  center  of 
gravity  of  the  plunger  is  generally  located  about  %"  from  the 
center  of  rotation,  and  the  scale  or  strength  of  the  spring  is  so 
selected  that  when  the  plunger  begins  to  move  outwards  the 
centrifugal  force,  acting  on  the  plunger,  increases  more  rapidly 
than  the  pressure  of  the  spring.  The  travel  of  the  plunger, 
when  it  is  tripped,  is  limited  by  the  shoulder  "  D." 

The  automatic  stop  should  operate  at  about  10%  or 
12%  above  normal  speed,  and  when  it  has  once  been  adjusted, 
should  not  require  adjustment,  unless  it  has  been  apart  for 
cleaning  or  inspection.  When  the  automatic  stop  has  been 
taken  apart,  either  for  adjustment  or  cleaning,  care  should  be 
taken  to  put  back  the  cotter  pin,  which  prevents  the  nut  from 
unscrewing. 

24 


Periodically,  the  automatic  stop  should  be  tested  to 
see  that  it  is  operating  properly,  which  may  be  done  by  pulling 
up  on  the  governor  valve  stem,  thus  permitting  the  turbine  to 
over  speed,  and  noting  the  speed  at  which  the  automatic  stop 
trips.  This  should  be  done  several  times  and  the  operator 
should  insure  himself  that  the  stop  trips  within  2  or  3%  of  the 
same  speed  several  times  in  succession,  to  make  sure  that  the 
stop  is  not  tripped  from  the  slight  vibration  of  the  shaft.  Also, 
to  insure  that  the  stop  is  not  sticking. 

When  the  automatic  stop  plunger  flies  out,  it  strikes  the 
automatic  stop  trigger  shown  in  the  cross  section,  Fig.  16, 
which  is  attached  to  the  throttle  valve  latch  rod,  throwing  it 
in  the  direction  of  the  arrow  and  releasing  the  throttle  valve 
latch,  which  permits  the  spring  in  the  automatic  throttle  valve 
to  close  the  valve. 

Automatic    Throttle    Valve     and    Governor    Valve. 

A  detailed  assembly  of  the  automatic  stop  and  governor  valve 
is  shown  in  Fig.  16,  from  which  the  construction  is  easily  seen. 
The  steam  enters  in  the  space  around  the  steam  strainer, 
which  surrounds  the  automatic  stop  valve,  and  prevents  any 
scale  or  other  extraneous  material  from  entering  the  turbine. 

The  stop  valve  is  of  the  balanced  type,  and  operates  as 
follows:- — When  closed,  the  throttle  valve  by-pass  valve  is  on 
its  seat,  thus  preventing  the  escape  of  steam  from  the  space 
"C"  into  the  space  below  the  valve,  which  is  at  atmospheric 
pressure.  Steam,  therefore,  which  leaks  between  the  throttle 
valve  piston  and  cylinder,  on  the  lower  part  of  the  throttle 
valve  yoke,  enters  the  space  "C"  and  holds  the  valve  firmly 
upon  its  seat.  When  the  throttle  valve  hand  wheel  is  turned 
to  open  the  valve,  the  throttle  valve  bypass  valve  is  raised 
from  its  seat,  permitting  the  steam  in  the  space  "  C  "  above  the 
throttle  valve  piston  to  assume  the  same  pressure  as  below  the 
valve  disc.  This  renders  the  valve  practically  balanced,  per- 
mitting it  to  be  readily  moved  by  further  motion  of  the  hand 
wheel  until  the  throttle  valve  stem  collar  comes  against  the 
throttle  valve  stem  nut.  The  throttle  valve  stem  nut  is  loose, 
and  free  to  move  up  and  down  within  the  extension  of  the 
throttle  valve  yoke.  In  the  position  shown  in  Fig.  16,  the 
throttle  valve  is  closed  and  the  throttle  valve  stem  nut  is  in 
its  upper  position,  being  held  there  by  the  throttle  valve  latch 
which  has  been  mentioned,  and  remains  in  the  position  in- 
dicated until  released  by  the  tripping  of  the  automatic  stop. 
The  throttle  valve  stem  nut  is  kept  from  turning  by  the  throttle 
valve  latch,  which  acts  as  a  dowel.  When  the  throttle  valve 

25 


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26 


latch  is  released  by  the  tripping  of  the  automatic  stop,  the 
pressure  of  the  throttle  valve  spring  on  the  throttle  valve  stem 
nut  forces  the  latter  downward,  closing  the  valve,  providing 
the  latter  has  been  opened. 

From  the  construction,  it  will  be  evident  that  the 
throttle  cannot  be  opened  after  it  has  been  tripped  by  the 
automatic  stop,  until  the  throttle  valve  hand  wheel  has  been 
turned  around  in  the  direction  required  to  close  the  valve,  and 
until  the  throttle  valve  stem  nut  is  brought  to  its  upper  posi- 
tion, and  has  caused  the  throttle  valve  latch  guide  rod  to  en- 
gage with  the  throttle  valve  latch,  and  hold  it  in  the  position 
shown  in  Fig.  16.  Furthermore,  it  will  be  evident  that  the 
automatic  releasing  of  the  throttle  valve  is  possible  in  any 
position,  whether  wide  open,  or  only  partially  open. 

The  steam  after  passing  through  the  automatic  throttle 
valve,  enters  the  space  above  and  below  the  governor  valve. 
The  latter  is  of  the  double  disc  poppet  construction,  thus  being 
entirely  balanced  for  steam  pressure.  The  only  force  required 
to  move  it,  is  that  necessary  to  overcome  a  slight  friction  of 
the  valve  stem  in  the  valve  stem  bushing  and  valve  cage 
guides.  As  will  be  noted,  from  the  cross  section,  the  valve 
cage  is  not  bolted  into  the  steam  chest  body  but  is  held  on  its 
seat  by  means  of  a  spring  which  permits  it  to  expand  and  con- 
tract without  warping  the  valve  seats.  The  lower  end  of  the 
valve  cage  is  free  to  expand  and  contract  without  resistance, 
steam  tightness  being  obtained  by  the  valve  body  being  ground 
into  the  steam  chest,  and  the  governor  valve  cage  spring  seat 
and  governor  valve  cage  spring  seat  ring,  shown  in  the  draw- 
ing. The  valve  is  so  constructed  that  it  has  to  be  moved  about 
1/32 "  before  steam  begins  to  pass,  thus  preventing  cutting  of 
the  valve  and  valve  seats  when  steam  is  being  throttled 
through  the  valve  at  light  load. 

Steam  tightness,  where  the  valve  passes  through  the 
valve  bonnet  is  obtained  by  a  plain  bronze  bushing  and  a 
small  soft  packing  washer,  which  need  not  be  made  very  tight, 
however,  as  any  steam  leaking  past  the  bushing  will  escape 
through  the  drain  port  "O."  A  more  elaborate  metallic 
packing  of  well  known  type  is  employed  in  the  larger  sizes. 


27 


The  Westinghouse  Machine  Company 

Designers  and   Builders  of 

Steam  Turbines  Stokers 

Steam  Engines  Gas  Producers 

Gas  Engines  Pumps 

Condensers  Blowers 

Turbo  Compressors 


SALES  OFFICES 

New  York 165  Broadway 

Chicago 39  South  La  Salte  Street 

Pittsburgh Westinghouse  Building 

Philadelphia 1003  North  American  Building 

Boston 201  Devonshire  Street 

Atlanta Candler  Building 

Denver Gas  &  Electric  Building 

Detroit 27  Woodward  Avenue 

Cleveland 1117  Swetland  Building 

Cincinnati 1 102  Traction  Building 

San  Francisco Hunt  Mirk  &  Co.,  141  Second  St. 

City  of  Mexico Cia  Ingeniera,  Importadora  y  Contratista,  S.  A. 

Havana,  Cuba Galban  &  Company 

San  Juan.  Porto  Rico Porto  Rico  Construction  Co. 

Iquique,  Chile J.  K.  Robinson  &  Co. 

Tokio,  Japan Takata  &  Company 

Caracas.  Venezuela.  .  . H.  I.  Skilton 


GENERAL  OFFICES  AND  WORKS 

EAST   PITTSBURGH,  PA. 


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